At a loss...

pmparents

New Member
Joined
Jun 29, 2007
Hey folks, I have a 87' GN, I'm new to the GN game but not the GN world. I've wanted this car since I was a kid and now I have one! I'm not completely lost when it comes to cars, but my GN is giving me some trouble and I wanted to know if anyone could offer some info.

She has bosch bluetop injectors, torque strap, TH 3" downpipe, I believe to be a 49 turbo, intake kit/w K&N filter, fuel pressure gauge, High performance CAT, catback exhaust, and a scanmaster. I put on new powermaster 140 amp alt., new 8mm spark plug wires, and a new ignition module. The car sat for a while and the previous owner said he believed he got some bad gas in her. At idle she's pretty much ok, but when i give gas theres hesitation/miss. It sounds like from other threads I read that injectors may be clogged/bad. I really don't think it's the fuel lines, filter, pump, etc. because the fuel pressure is where it's supposed to be.

Any help would be appreciated! I don't wanna change the injector's and it's something else.
 
Drain the gas and put in some new gas and some new plugs in and try that first. Let us know what it does then.
Tarey D.
 
and try the 'MAF Thump' during the rotten running event. Unikely cause...but could be..and easy as a thump away. If you thump the MAF and idle changes, there you have it.

Best to rule out all the easy, no cost, testing first, before you go replacing parts.
 
Car sat for awhile

As someone mentioned get her some good gas, while your doing that you might as well put a injector cleaner in, like Lucas, do the MAF tap. I'd also think about putting a new fuel filter, because the car has sat for a time, it may not just be bad gas but dirty gas. We might be throwing our money away but we usually put injector cleaner quaterly. Also use carb cleaner to clean the upperend/intake/exhaust. Put/spray carb cleaner into a small can and take off vacuum hose off top of FPR , start engine and suck it up. The engine will hickup and try to stall ,I'll have my son give it some throttle/gas to keep her from stalling out , man you wouldn't believe the crap/soot that comes out, you'd think you were running a diesel .

Take O2 sensor out so it doesn't get all that varnish/oil/carbon deposits thats being cleaned off the inside of the intake/doghouse and going out exhaust. Reason we do it is because we have one those engines that vacuum sucks up oil mist thru the PVC . We do it anyway even though there is a catch can/oil air seperator between PVC and doghouse.

Most importantly as you know being around GN's Buy/Beg/ Borrow/steal a Scan Tool and set IAC, TPS, see what MAF #s are, O2 counts/volts, KR, INT/BLMs refer to Spring Cleaning list at gnttype.org . Get all the basics done 1st which you may have done already, if so then troubleshoot and fine tune. Make sure she has the correct chip for your combo.
 
figured out the misfire part

I figures out the misfiring. When I changed the sparkplug wires, 2 wires were in the wrong place. Something told me to check again, since that was the last thing I did.

Now runs good for the most part, but still hesitates while driving. I give her gas and she clears up. The fuel pressure gauge is where it's supposed to be, so I'm really thinking the injectors are clogged or bad. I already put some Lucas in her, things are still the same. I didn't put the whole bottle in though. This weekend I'm changing the fuel filter and I'm gonna test the 2 other computers I have also, 1 has a turbo tweaks chip in it.

Tell me what you think!
 
I forgot one whole side off once when i re-torqued the heads on my car and it ran pretty decent put if i touched the throttle it would stumble, lol
,Dan
 
I figures out the misfiring. When I changed the sparkplug wires, 2 wires were in the wrong place. Something told me to check again, since that was the last thing I did.

Now runs good for the most part, but still hesitates while driving. I give her gas and she clears up. The fuel pressure gauge is where it's supposed to be, so I'm really thinking the injectors are clogged or bad. I already put some Lucas in her, things are still the same. I didn't put the whole bottle in though. This weekend I'm changing the fuel filter and I'm gonna test the 2 other computers I have also, 1 has a turbo tweaks chip in it.

Tell me what you think!


Get a scantool and set your IAC. GET A SCANTOOL like a SCANMASTER.
 
Reason I ask is because the tuning article says that the IAC has know effect off Idle. (This IAC solenoid is controlled by the ECM and compensates for varying engine load at idle. Once off idle, the IAC has no affect on performance) I'm just trying to understand, all new!
 
but an improperly adjusted one can cause a 'tip-in stumble' which maybe what you are calling hesitation
 
Thanks Wendy, i checked the IAC with my scan master and it was reading between 86 - 92. I'm gonna adjust it this weekend.
 
Top